Re: [PATCH v1 2/3] perf version: Print the status of compiled-in libraries

["Jin, Yao" <yao.jin@linux.intel.com>]

On 3/27/2018 8:56 PM, Jiri Olsa wrote:
> On Tue, Mar 27, 2018 at 09:44:23AM +0800, Jin, Yao wrote:
>>
>>
>> On 3/26/2018 5:39 PM, Jiri Olsa wrote:
>>> On Tue, Mar 27, 2018 at 12:07:03AM +0800, Jin Yao wrote:
>>>> This patch checks the values passed by CFLAGS (-DXXX) and then
>>>> print the status of libraries.
>>>>
>>>> For example, if HAVE_DWARF_SUPPORT is defined, that means the
>>>> library "dwarf" is compiled-in. The patch will print the status
>>>> "on" for this library.
>>>>
>>>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>>>> ---
>>>>    tools/perf/builtin-version.c | 125 +++++++++++++++++++++++++++++++++++++++++++
>>>>    tools/perf/builtin.h         |   1 +
>>>>    2 files changed, 126 insertions(+)
>>>>
>>>> diff --git a/tools/perf/builtin-version.c b/tools/perf/builtin-version.c
>>>> index 37019c5..90a0a7f 100644
>>>> --- a/tools/perf/builtin-version.c
>>>> +++ b/tools/perf/builtin-version.c
>>>> @@ -9,3 +9,128 @@ int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused)
>>>>    	printf("perf version %s\n", perf_version_string);
>>>>    	return 0;
>>>>    }
>>>> +
>>>> +static void status_print(const char *name, const char *status)
>>>> +{
>>>> +	printf("%22s: [ %3s ]\n", name, status);
>>>> +}
>>>> +
>>>> +static void library_status(void)
>>>> +{
>>>> +#ifdef HAVE_DWARF_SUPPORT
>>>> +	status_print("dwarf", "on");
>>>> +#else
>>>> +	status_print("dwarf", "off");
>>>> +#endif
>>>
>>> could this and all those below be in some generic macro?
>>>
>>> #define STATUS(__d, __m)		\
>>> #ifdef __d 				\
>>> 	status_print(#__m, "on");	\
>>> #else					\
>>> 	status_print(#__m, "OFF");	\
>>> #endif
>>>
>>> STATUS(HAVE_DWARF_SUPPORT, dwarf)
>>>
>>>
>>
>> Hi Jiri,
>>
>> I have tried this macro definition, but unfortunately the compilation is
>> failed.
>>
>> error: '#' is not followed by a macro parameter
>>   #define STATUS(__d, __m)  \
>>
>> I just guess the '#' in #ifdef confuses the gcc. Looks we can't define
>> #ifdef/#endif block in a macro.
>>
> 
> ah crap.. right ;-) how about we take the IS_BUILTIN thingie
> from include/linux/kconfig.h and use it as in attached test
> change.. it gives me:
> 
> 	[jolsa@krava perf]$ ./perf version
> 	perf version 4.16.rc6.g1ee9a60
> 			 dwarf: [  on ]
> 			 krava: [ OFF ]
> 
> we could put those macros into tools/include/tools/config.h, Arnaldo?
> together with the comments from kconfig.h that I cut out..
> 
> thanks,
> jirka
> 
> 
> ---
> diff --git a/tools/perf/builtin-version.c b/tools/perf/builtin-version.c
> index 1fe458792cc1..b392f9e80fd0 100644
> --- a/tools/perf/builtin-version.c
> +++ b/tools/perf/builtin-version.c
> @@ -6,8 +6,33 @@
>   
>   int version_verbose;
>   
> +
> +#define __ARG_PLACEHOLDER_1 0,
> +#define __take_second_arg(__ignored, val, ...) val
> +
> +#define __is_defined(x)                 ___is_defined(x)
> +#define ___is_defined(val)              ____is_defined(__ARG_PLACEHOLDER_##val)
> +#define ____is_defined(arg1_or_junk)    __take_second_arg(arg1_or_junk 1, 0)
> +
> +#define IS_BUILTIN(option) __is_defined(option)
> +
> +
> +static void status_print(const char *name, const char *status)
> +{
> +	printf("%22s: [ %3s ]\n", name, status);
> +}
> +
>   int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused)
>   {
>   	printf("perf version %s\n", perf_version_string);
> +
> +#define STATUS(__d, __m)			\
> +	if (IS_BUILTIN(__d))			\
> +		status_print(#__m, "on");	\
> +	else					\
> +		status_print(#__m, "OFF");
> +
> +	STATUS(HAVE_DWARF_SUPPORT, dwarf)
> +	STATUS(HAVE_KRAVA_SUPPORT, krava)
>   	return 0;
>   }
> 

Hi Jiri,

It looks we need to copy the IS_BUILTIN and associated macro definitions 
to a common header file.

I guess you will post this patch if Arnaldo agree with this idea, right?

I plan to post v2 of this patch series after this 'IS_BUILTIN' patch 
gets merged.

Thanks
Jin Yao